Xavier nx fan pwm control

[tal.roey]

Hi Team

What is the fan pwm freuency range of the xavier nx
Please dont send me to some SW related code, i am a hardware engineer

Regards,
Roey

[kayccc]

Please check L4T doc: NVIDIA Jetson Linux Driver Package Software Features : Clock Frequency and Power Management | NVIDIA Docs

[tal.roey]

Again, I am not SW engineer so dont point me to some BSP documents
The question is simple what is the frequency of the PWM? Not the duty cycle but the frequency itself.
If this frequency can be selected then what is the range?

Thanks,
Roey

[JerryChang]

hello tal.roey,

that’s depends-on the clock source, there’re possible clock parents of pwmN.
i.e. $ cat /sys/kernel/debug/bpmp/debug/clk/pwmN/possible_parents

you may check the current rate of pwmN via sysnode, the unit is in Hz.
for example, $ cat /sys/kernel/debug/bpmp/debug/clk/pwmN/rate

furthermore,
you should know the clock sources if you would like to check its max/min rate,
here’s an example to calculate possible rate of a PWM controller, its clock source pllp_out0 which has a rate of 102 MHz.
Max Rate = 102Mhz/ 256 = 398437 Hz = 2510 ns
Min Rate = 102Mhz/ (256* 2^13) (i.e. 13-bits Frequency divider (bits 0:12)) = 48.63Hz = 20561324 ns

[tal.roey]

Thanks alot fot the explanation